Project Summary Heavy alcohol use in HIV-infected patients contributes to suboptimal adherence to antiretroviral therapy (ART), greater sexual risk taking, higher viral loads, and worsened liver and cognitive functioning. Gay, bisexual, and other men who have sex with men (MSM) continue to represent almost half of all HIV/AIDS cases in the United States, and heavy drinking is particularly high among this HIV-infected sub-group. Brief motivational interventions have been shown to reduce alcohol consumption among HIV-infected MSM; however, these individual-level interventions have demonstrated only modest effects in reducing drinking in this population, indicating that sustained behavior change requires attending to social and interpersonal contexts as well. To date, there are no existing brief, couples-based interventions to address heavy alcohol use among HIV-infected MSM and their primary partners that do not require alcohol abstinence treatment goals. Furthermore, there are no published data on the extent to which changes in couples alcohol use relate to key HIV-related outcomes (ART adherence, viral suppression, sexual risk). The overall aim of this project is to develop and test the feasibility, acceptability, and preliminary efficacy of a brief couples-based motivational intervention to address heavy alcohol use among HIV-infected MSM and their primary partner. This treatment development project builds on our individual-level motivational intervention (MI) with HIV- infected MSM by using components from our significant other-involved motivational intervention (SO-MI) and couples-based HIV prevention interventions, and seeks to provide insights into the mechanisms of couple-level behavior change, including motivation, individual and dyadic self-efficacy, and partner support. A two-step sequence of treatment development will be used to achieve these aims. Stage 1a includes interviews with key informants (N = 15 couples), manual development, therapist training, and a one-arm pilot with qualitative exit interviews (N = 12 couples). Stage 1b consists of a small-randomized clinical trial in which 50 heavy drinking HIV-infected MSM will be randomly assigned to either couples intervention, which involves participation of their partner, or to the existing individual intervention, which does not. Both conditions will consist of four sessions conducted over a one-month period. Participants will be interviewed at baseline, and 3-months and 6-months. Findings will provide data on the feasibility, acceptability and preliminary efficacy of the couples-based motivational intervention to reduce alcohol use among HIV- infected MSM and their primary partners. If this research shows initial promise, we will use findings to support an R01 application to test the intervention efficacy in a fully powered randomized controlled trial. This research could provide a foundation for improving the health of HIV-infected heavy drinking MSM.